A universal mobile telecommunications system (UMTS) is a third generation (3G) mobile communication system that adopts the wideband code division multiple access (WCDMA) air interface technology. The UMTS is also called a WCDMA communication system. In the UMTS system, the coverage areas of adjacent cells may overlap. The UMTS system may provide seamless handover by using soft handover technology, and the achieved gains through macro diversity combining (MDC) may increase the anti-interference capability of the UMTS system.
3G technologies are evolving along with the development of mobile communication technologies. High speed uplink packet access (HSUPA) is introduced in Release 6 (R6) of the 3GPP. HSUPA also supports the uplink macro diversity technology.
The implementation process of MDC is briefed as follows. During the soft handover, a UE and multiple base stations communicate through two different air interface channels at the same time. On the uplinks, the multiple NodeBs receive uplink user data in code-division channels of the UE. All the multiple NodeBs send the received uplink user data to a radio network controller (RNC) for selection and combination. The RNC selects the better uplink user data from the uplink user data sent by the multiple NodeBs by using a frame reliability indicator for outer loop power control, and sends the selected data to the core network.
The preceding network architecture is based on architectures of versions earlier than 3GPP R6. To prolong the lifecycle of the WCDMA system and protect the operator's investments, the 3GPP proposes a research program on an evolved high speed packet access (E-HSPA) evolution, aiming to improve spectrum efficiency based on R6 and reduce the delay of the control plane and user plane. In addition, the purpose of the program is to realize that E-HSPA is compatible with earlier versions and is able to evolve into the long term evolution/system architecture evolution (LTE/SAE) system smoothly, including improvement of air interface performance and evolution of radio access network (RAN) architecture.
In an E-HSPA network, the RNC's functions are transferred to an E-HSPA NodeB (NodeB+). The NodeB+ is directly connected to the core network through the IuPS interface.
The process of implementing MDC on the E-HSPA network is as follows. Uplink MDC is implemented in a serving NodeB of the user. For data on all the radio links in an active set, if the received data on a radio link corresponding to a non-serving NodeB is correct, the non-serving NodeB sends the uplink data to the serving NodeB; after performing MDC on the received uplink data, the serving NodeB sends the data to the core network. This solution is similar to the MDC implementation solution in the RNC of a current 3G system except that the functions are implemented by the serving NodeB other than by the RNC. If the uplink macro diversity is implemented in the serving NodeB (including the serving RNC function), communications between NodeBs are necessary. If other soft-handover NodeBs send received uplink data to the serving NodeB for macro diversity processing, the interface between NodeBs may have transmission overload (last-mile transmission resource) and the user plane may have delay.
During the implementation of the present invention, the inventor finds at least the following problem in the prior art. During the MDC implementation in a WCDMA system using HSUPA or E-HSPA, a non-serving NodeB always needs to allocate demodulation resources for all the service data. In practical applications, some services with certain features (for example, the high-speed non-real-time service) obtain only small gains by using MDC. Thus, it is not worth the candle in terms of the system as a whole to obtain only small gains with a large quantity of demodulation resources.
To sum up, the prior art does not fully consider the fact that services with different features may obtain different gains by using MDC but always requires demodulation resources, thus wasting demodulation resources.